Conventionally, an optical fiber that transmits an optical signal has been used for connecting optical members such as a laser diode, a photodiode, a coupler, an isolator and the like (see, for example, International Publication Pamphlet No. 05/103779).
FIG. 4A and FIG. 4B are schematic diagrams for illustrating a conventional optical fiber splicing technique.
In FIG. 4A, one end of an optical fiber F is connected to optical members 42-47 such as a laser diode, a photodiode, a coupler, an isolator and the like mounted on an optical member unit 41. Another end of the optical fiber F is drawn outside the optical member unit 41 in which the optical members are stored. The optical fibers F are held by a pair of fiber holders 49 in a fusion splicing machine 48 such that the optical fibers F to be connected face each other.
Then, as depicted in FIG. 4B, in the optical fibers F connected by fusion splicing by the fusion splicing machine 48, the part F′ drawn outside is bent and stored in the storage area
Meanwhile, as the sizes of various products have been reduced recently, there has been a need for mounting optical members with a narrow pitch. However, an optical fiber cannot be folded, and a certain bending R (for example equal to or more than R 30 mm) needs to be secured.
For this reason, as depicted in FIG. 5A, when connecting optical fibers F extending from adjacent optical members 52 and 53 to the same direction (to the right in FIG. 5A) by fusion splicing while making them face each other in fiber holders 54, the optical fiber F for example connected to the optical member 53 has to be turned around to a large extent, in order to secure a certain bending R for the optical fiber F.
In addition, with the mounting position of the members as that for the optical member unit 51′ depicted in FIG. 5B, the optical fiber F (the optical fiber connected to the optical member 52′ is not depicted in the drawing) needs to be turned around in a more complicated way, in order to draw the optical fiber F connected to the optical member 53 outside towards fiber holders 54.
There has been a problem that, forming work conducted while making the optical fiber turn around in a complicated way as described above leads to a poor forming workability.